circuit difference measurement,

Hello,
I need to design a V-I impedance measurement interface for frequencies below 50MHz. What circuit is suitable for measuring phase difference? I need some circuit examples or a book/paper recommendation about this.

Thanks

Hello,

I think the best way for high dynamic, noise insensitive phase determination for a network respectively impedance analyzer circuit is from vectorial measurement. This way it is done in GHz as well as in low frequency instruments. This technique implies either a synchronous demodulator or digital signal processing. As an example for a low frequency impedance measurement see Analog Devices AD5933 Network Analyzer IC.

Regards,
Frank

You can use for phase measurements the circuit AD8302 from Analog Devices (you can get free samples)
http://www.analog.com/UploadedFiles/...ets/AD8302.pdf